The tentative four-year agreement with the International Association of Machinists and Aerospace Workers union would cover 7,700 employees, primarily baggage handlers and ramp personnel. The contract is subject to ratification by union members and voting is expected to take three to four weeks.

The Tempe-based airline has been working to put single contracts in place for workers at its America West Airlines and US Airways operations. America West acquired US Airways in Sept. 2005.

The airline and the machinist's union have been negotiating for more than a year and began voluntary meetings with the National Mediation Board last week.

The machinist's union also represents the airline's maintenance and related workers, and mediators are involved in those ongoing negotiations.

"Today's announcement moves us another step closer to a unified airline and our goal of bringing our remaining groups to single labor agreements," US Airways Chairman and Chief Executive Doug Parker said in a statement.

The company and the Air Line Pilots Association are still operating without a combined contract. Negotiations that have pitted pilot union groups for the two airlines against each other are ongoing. The company also is trying to hammer out an agreement with its two flight attendant groups.

The airline previously reached combined contract deals with its airlines reservations and service workers and flight dispatchers, instructors and engineers.